Comparison of soda ash quality!
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What is the actual difference between soda ash produced by the ammonia-alkali process and that produced by the double-soda process?
The main specifications for soda ash produced by the ammonia-alkali process are as follows: the primary content of light ash is Na2CO3 > 99.4%, NaCl at 99.4%, NaCl at 93%, and the bulk density is 0.92 g/m3
Sodium hydroxide light ash: 500–600 kg/m3, softness degree 50; heavy ash: 1000–1200 kg/m3, softness degree 45
The difference in product quality between soda ash produced by the ammonia-soda process and that produced by the double-soda process lies mainly in the processing steps related to saltwater. In the ammonia-soda process, raw salt or saturated brine is refined – that is, calcium and magnesium are removed before soda ash is produced. While the double-soda process does involve salt washing, solid salt is added directly through cold crystallization; as a result, impurities present in the solid salt end up being incorporated into the system to varying degrees, which affects the quality of the product.
In the double-alkali process, which is a cyclic process, there are restrictions on the amount of water used for filtering and washing the product in order to prevent issues such as mother liquor expansion; as a result, the quality of the final product is primarily reflected in the level of salts present. The ammonia-alkali process involves brine purification and generates waste liquid; there is ample room to implement process measures in brine purification and the filtration and washing of concentrated alkali, thereby ensuring a low salt content in the product.
The water-insoluble substances in the products of the combined-alkali process are higher than those in those produced by the ammonia-alkali process; moreover, the salt content in the former is higher than that in the latter!
It seems that LZ is asking about the differences in product quality between the two processes: ammonia-alkali process and combined-alkali process.